Because [Xaku] doesnt already have enough kpm (irony off) i made this Nourish build for the extra viral procs. (Also no Arcane Energize needed thanks to Nourish.)

Each time you take damage Nourish will proc its viral on to enemies and this happens nonstop because thanks to [Combat Discipline] you lose 1 health each kill which can also trigger Arcane Grace to keep you alive. (Arcane Blessing works too if you get enough health orbs, [Synth Deconstruct] can help with that.)
It will also keep Arcane Avenger active to give you 45% crit chance on your weapons. Also you dont have to mod your weapons for viral because nourish gives you that without mods when active.

To make this more comfortable i put 4 tauforged red shards on [Xaku], each one giving +15 duration (160 in total) so no need for [Primed Continuity] which will open a slot for [Augur Reach] to go max range. 1 Red shard has to be +10 or +15 strengh (i have [Blind Rage] on 9 for the sake of min maxing) to have exactly 200% strengh which is needed to have 100% defense reduction on your 3rd.

You only need 1 umbra forma if you upgrade [Combat Discipline] on 1, polarize the exilus slot and use normal [Stretch] instead of [Archon Stretch] which will only give slight value if there is a [Wisp] in your squad which gives you the shock mote.

Ps. You can abuse the +100 range buff you can get from collecting 10 reactants when opening relics by literally just casting your 4th right in time before it runs out so you can keep the extra weapons and shooting range you get when casting 2 with the reactant buff for about 15min, usually long enough to get to the next buff.

For total annihilation stack it with +100 range from the helminth invigoration and go crazy.

And since you wont get any weapon kills yourself with like 50 guns shooting around you with insane 480 range i just bring one weapon to get the warframe buff more often.

I hope you enjoy :3